CFD simulation of internal-loop airlift reactor using EMMS drag model--颗粒学报PARTICUOLOGY

Xu, T., Jiang, X., Yang, N., & Zhu, J. (2015). CFD simulation of internal-loop airlift reactor using EMMS drag model. Particuology, 19, 124–132. https://doi.org/10.1016/j.partic.2014.04.016

CFD simulation of internal-loop airlift reactor using EMMS drag model

Tingting Xu ^{a b}, Xuedong Jiang ^{a c}, Ning Yang ^a *, Jiahua Zhu ^d

a State Key Laboratory of Multi-Phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China
c Department of Chemical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
d School of Chemical Engineering, Sichuan University, Chengdu 610065, China

10.1016/j.partic.2014.04.016

Volume 19, April 201, Pages 124-132

Received 17 February 2014, Accepted 22 April 2014, Available online 8 September 2014.

E-mail: nyang@home.ipe.ac.cn

Highlights

• DBS drag model based on EMMS approach was used for simulating internal-loop airlift reactors.

• CFD simulation with S–N or DBS drag models were compared to published experimental data.

• The S–N drag model in commercial CFD package failed to predict gas holdup in downcomer.

• DBS drag model greatly improved gas holdup prediction in downcomer and riser.

Abstract

The simulation of internal-loop airlift reactors is challenging because complex meso-scale structures exist in different sections of the reactor, separated by the draft tube. This paper reports on the computational fluid dynamics (CFD) simulation of internal-loop airlift reactors using a new drag model derived from the dual-bubble-size (DBS) model, an extended energy-minimization multi-scale (EMMS) approach for gas–liquid flows. Compared with the traditional Schiller–Naumann (S–N) correlation, the new model improves the simulation of gas holdup in the riser and downcomer significantly. In particular, gas holdup and circulation of two-phase flow can be modeled successfully using the new model, whereas traditional drag models such as the S–N correlation show an absence of gas in the downcomer. The simulation demonstrates the advantage and potential of this new model for internal-loop airlift reactors.

Graphical abstract

Keywords

Computational fluid dynamics; Internal-loop; Airlift; Multi-scale; Multiphase flow; Hydrodynamics

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